Esters of 4-cyclohexene-1, 2-dicarboxylic acid



Patented Mar. 3, 1942 ESTERS OF l-UYCLO-LZ-DICAR- BOXYLIC ACID 1 Clarence L. Moyle, Midland, Mich.,

The Dow Chemical Company, a corporation of Michigan assignor to Midland, Mlch.,

No Drawing. 1 Application May 2, 1041, Serial No. 391,4:1

12Claims.

This invention concerns new esters of 4-cyclohexene-Lz-dicarboxylic acidand certain allyltype alcohols, i. e. alcohols of the general formula:

wherein R represents a simple neutral substituent of the group consisting of the methyl radical. hydrogen, and halogen, R represents a member of the group consisting of the methyl radical and hydrogen, and R." represents a'member of the group consisting of hydrocarbon radicals and hydrogen.

The esters provided by the invention vary from crystalline solids to colorless to yellow, high boiling. mobile or somewhat viscous liquids. They have insecticidal properties and can also be used as plasticizers, as light stabilizers for .vinylidene chloride resins. and as co-polymerizing agents with styrene.

The new esters are prepared by reacting 4- cyclohexene-lZ-dicarboxylic acid with the allyltype alcohols, such as allyl alcohol, geraniol, cinnamyl alcohol, etc. The mono-esters are prepared preferably by using approximately equimolar proportions of the acid and alcohol. The

di-esters are prepared preferably with an excess of alcohol and in the presence of a small amount of an acid catalyst such as benzene sulfonic acid. A wide range of temperatures may be used, but it is preferred to carry out the reaction at a temperature below about 135 C. inorder to avoid possible decomposition of the products. Water formed during the reaction is removed as an azeotrope, distilling together with a portion of the alcohol. The oily residue is washed with an aqueous alkali and distilled under reduced pressure. Although the method described is preferred, any suitable esterii'lcation method may be used, provided that care is taken to prevent decomposition or polymerization of the ester product. a

The following examples illustrate a number oi ways in which the principle of the invention may be employed, but are not to be construed as limiting the invention.

Example 1 93 grams (0.6 mole) of 4-cyclohexene-l3-dicarboxylic acid anhydride and 209 grams (3.6 moles) of allyl alcohol were reacted in the presence of 1 gram of benzene sulfonic acid ascatalyst. Water was distilled from the reaction mixture as an azeotrope with the excess allyl alcohol. The oily residue remaining after the distillation was washed with anequeous sodium bicarbonate solution, dried, and distilled. The ester, diallyl 4-cyclohexene-1,2-dicarboxylate. distilled as a colorless liquid. It has a boiling point of 150-152 C. at 8 millimeters pressure, a speciflc gravity at 25/25 of 1.09, a refractive index at 25 of 1.4840, and the formula:

Example 2 This ester is a colorless mobile liquid havinga boiling point of 150-160 C. at 4.5 millimeters pressure. a specific gravity 8 a refractive index at 25 of 1.4693.

Example 3 H; CHI

This-ester is a yellow slightly viscous oil having a boiling point of 234-244 C. at 3.5 millimeters at 25725" of 1.03, and

a refractive index at 25 of 1.4902.

. Example 4 93 grams (0.6 mole) of 4-cyclohexene-L2- dicarboxylic acid anhydride and 336 grams (3.6 moles) of 2-chloroallyl alcohol were reacted at a temperature of 115-135 C. in the presence of 1 gram of benzene sulfonic acid at 150 millimeters pressure. The product was the (ii-(2- chloroallyl) boxylic acid. It has the formula:

This esteris a pale yellow mobile liquid having a boiling point of 185-190 C. at 18 millimeters pressure, a specific gravity at 25/25 of 1.24, and a refractive index at 25 of 1.5039.

Example 5 A mixture of 152 grams (1 mole) of 4-cyclohexene-l,2-dicarboxylic acid anhydride and 58 grams (4 mole) of allyl alcohol was heated for 6 hours under reflux on a steam bath. The product was then concentrated on a hot plate until the temperature of the residue reached 108 C; The ester product was the monc-ailyl ester of 4-cyclohexene-1,2-dicarboxy1ic acid. It has the formula:

This ester is a viscous pale orange colored oil which'slowly crystallizes on standing. It has a refractive index at 25 C. of 1.4971.

Example 6 A mixture of 38 grams (0.25 mole) of -cyclohexene-1,2-dicarboxylic acid anhydride and 34 grams (0.25 mole) of cinnamyl alcohol was heated for six hours under reflux on a steam bath. Upon cooling, a viscous liquid remained. The latter was dissolved in 250 c. c. of 2N sodium hydroxide and the solution was extracted with ethylene dichloride to'remove di-esters and any unreacted alcohol. The aqueoussolution was acidified with dilute hydrochloric acid and the product was extracted from the mixture with ethylene dichloride. The ester product, which was obtained by evaporation of the solvent, was the mono-cinnamyl ester of 4-cyclohexene-L2- dicarboxylic acid. It has the formula:

This ester is a pale yellow viscous oil which crystallizes on standing. The crystals have a melting point of 87-88 C.

Other esters of the present invention are monoand di-2-bromoally1 4-cyclohexene-L2- dicarboxylate, monoand dicrotyl 4-cyclohexene-l,2-dlcarboxylate,, mono-chloroallyl 4-cyclohexane-1,2-dicarboxylate, etc.

I claim:

ester of 4-cyclohexene-L2-dicar- 2,276,034 pressure, a specific gravity at 25/20 of 0.94, and

1. An ester of 4-cyclohexene-1,2-dicarboxylic acid and an alcohol of the general formula:

wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen; R represents a member of the group consisting of the methyl radical and hydrogen; and R" represents a. member of the group consisting of hydrocarbon radicals and hydrogen.

2. An ester of 4-cyclohexene-1,2-dicarboxylic acid and an alcohol of the general formula:

HOCHr-&=CHR" wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen; and R represents a memberof the group consisting of hydrocarbon radicals and hydrogen.

3. An ester of 4-cyclohexene-1,2-dicarboxylic acid and an alcohol of the general formula:

R HO-CHz-$=CH wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen.

4. An ester of 4-cyclohexene-1,2-dicarboxylic acid having the general formula:

c B 'R' co-cHr-c=c-R" f)O-CH:C=CR" wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen; R represents a member of the group consisting of the methyl radical and hydrogen; and R" represents a member of the group consisting of hydrocarbon radicals and hydrogen.

5. An ester of 4-cyclohexene-1,2-dicarboxylic acid having the general formula:

wherein R represents a simple neutral substituent of the group consisting of the methyl radical,

hydrogen, and halogen and R" represents a member of the group consisting of hydrocarbon radicals and hydrogen.

6. An ester of 4-cyclohexene-1,2-dicarboxylic acid having the general formula:

wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen.

7. An ester-of 4-cyc1ohexene-1,2-dicarboxylic acid having the general formula:

'' COOH 2,875,084 I wherein R represents a simple neutral substituent of the group consisting of the methyl radical, hydrogen, and halogen; R represents a member of the group consisting of the methyl radical and hydrogen; and R" represents a member of 6 the group consisting oi. hydrocarbon radicals and hydrogen.

8. An ester of 4-cyc1ohexene-l,2-dicarboxylic acid having the general formula:

wherein R represents a simple neutral substituent or the group consisting of the methyl radical, hydrogen. and halogen: and R." represents a radicals and hydrogen.

9. An ester of d-cyclohexene-lJ-dicarboxylic acid having the general formula:

ate.

CLARENCE L. MOYLE.

member or the group consisting oi hydrocarbon 

